Bladed rotor,particularly for a compressor



July 22 1969 J. PALFREYMAN ETAL 3,456,917.

BLADED ROTOR, PARTICULARLY FOR A COMPRESSOR Filed Jan. 11, 1965 2. Sheets-Sheet 1 /4 /i 20 I po OOJO 01 raaam a 0 0', hzskaeiiaeai lnvenlurs mmzyaw z w July 22', 1969 A AAAAAAAAAA AL 3,456,917 ROTOR I nnnnnnn rs United States Patent 3,456,917 BLADED ROTGR, PARTICULARLY FOR A COMPRESSOR Jack Palfreyman, Tansley, near Matlock, and Norman Willie Shepherd, Shelton Lock, England, assignors to Rolls-Royce Limited, Derby, England, a company of Great Britain Filed Jan. 11, 1965, Ser. No. 424,658 Claims priority, application Great Britain, Jan. 15, 1964, 1,887/ 64 Int. Cl. F0111 /14; F0411 29/38 US. Cl. 25377 27 Claims ABSTRACT OF THE DISCLOSURE A bladed rotor of fiber-reinforced construction has respective pairs of blades which are interconnected by continuously curved and interwoven bundles of fibers. Each bundle of fibers, which is preferably of catenary form, is held in tension on rotation of the rotor.

This invention concerns a bladed rotor and, although it is not so restricted, it is more particularly concerned with a rotor of a gas turbine engine compressor.

According to the present invention, there is provided a bladed rotor comprising a hub portion, a plurality of blades united with said hub portion, at least part of each blade comprising fibers, and at least part of the hub portion comprising respective continuously curved and interwoven groups of fibers connecting each respective blade to another blade, whereby the fibers of each said group are in tension along their axes on rotation of the rotor.

The rotor may be formed of a plurality of groups, or bundles, of said fibres, opposite ends of each said bundle being used in the formation of different blades, and the central part of each bundle being used in the formation of the hub portion. Thus, the central part of each bundle may be divided into two spaced portions.

The said fibres employed in the formation of each blade of a diametrically opposite pair of blades may come from the same bundle or bundles, and in this case the spaced portions may be of catenary shape.

Alternatively, the spaced portions of each bundle may extend from a common blade to two different blades.

Preferably the spaced portions of the various bundles are interwoven with each other.

The hub portion may comprise at least two discs each of which carries a plurality of blades, the blades of each disc being connected to those of the adjacent disc by a group of said fibres.

The rotor may be made up of a plurality of laminae which have been united together, each lamina consisting of a part of both the hub portion and the blades.

The fibres may be of inorganic material; e.g. they may be formed of a ceramic oxide, nitride or carbide. Thus they may be formed of sapphire, or silica or silicon nitride, or silicon carbide.

Alternatively, the fibres may be formed from carbonaceous material such, for example, as graphite.

Yet another possibility is for the fibres to be formed of boron.

Each fibre may be individually coated with a metal or alley. For example, it may be coated with silver, or nickel or iron or titanium or platinum or columbium, or aluminium or any alloy thereof.

Alternatively, each fibre may be individually coated witth a synthetic resin material such for example, as an epoxy or polyimide, or polyimidazole, or polyquinoxaline, or polythiazole resin.

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The bladed rotor may, if desired, be formed of synthetic resin material reinforced by the said individually coated fibres.

The invention is illustrated, merely by way of example, in the accompanying drawings, in which:

FIGURE 1 is a diagrammatic perspective view of a rotor of a gas turbine engine compressor,

FIGURE 2 is a diagrammatic view showing the manner in which metal coated fibres are employed to form the blades and discs of the rotor of FIGURE 1,

FIGURE 3 diagrammatically illustrates the manner in which the said fibres are used to interconnect the blades of two discs of the rotor,

FIGURE 4 is a developed plan view looking in the direction of the arrow 4 of FIGURE 1, but with the blades removed, and

FIGURE 5 is a view similar to FIGURE 4 but illustrating a modification.

Referring first to FIGURES 1 to 4, a gas turbine engine compressor rotor 10 has a tub portion consisting of a cylindrical casing 11 and discs 12, 13. Each of the discs 12, 13 is provided with a plurality of angularly spaced apart blades 14. The blades 14, casing 11, and discs 12, 13 are formed, at least in part, of individually coated fibres 15, e.g. silica fibres which have been coated with aluminium or with an epoxy, or polyimide or polyimidezole, or polyquinoxaline or polythiazole resin.

Alternatively the fibres may be formed from a ceramic constituted by an oxide, nitride or carbide. The fibres may also be formed of sapphire, silica, silicon nitride or silicon carbide, coated with silver, or nickel, or iron, or an alloy thereof. Moreover, the fibres may be graphite or boron fibres coated with a synthetic resin (e.g. an epoxy or polyimide resin) or with a metal such, for example, as silver, nickel, platinum or columbium. Alternatively the blades 14, casing 11 and discs 12, 13 may be formed of a synthetic resin material, such for example as an epoxy or a high temperature polyimide resin, reinforced by any of the said coated fibres.

As shown in FIGURE 2 each of the discs 12, 13, together with its blades 14, are formed, at least in part, of a plurality of bundles of the said fibres 15. Opposite ends of each said bundle are used in the formation of diametrically oppositely disposed blades 14, the central part of each bundle being divided into two spaced portions continuously curved groups or bundles of fibers 16, 17 which are used in the formation of the discs 12, 13.

Thus each blade 14 is connected to another blade 14 by way of the respective two groups of fibers 16, 17 which extend through a respective one of the discs 12, 13.

As is clearly shown in FIGURE 2, each of the groups 16, 17 may have a catenary shape the various groups 16, 17 being interwoven with each other.

The formation of the groups 16, 17 in a catenary shape ensures that, during rotation of the rotor, all parts of these groups are in tension along their axes and this is desirable since, for example, aluminium coated silica fibres are strong in tension but weak in compression.

The blades 14 of the discs 12, 13 are interconnected by coated fibres 20 which may form part of the fibres employed in the formation of the blades 14 or may be constituted by wholly separate fibres. As shown best in FIGURE 4, the fibres 20 are arranged in a lazy-tong pattern embracing the roots of the blades 14 of the discs 12, 13. The angle a between adjacent limbs of the lazytong pattern is such that as the discs 12, 13 twist relatively to each other about the rotational axis the fibres will lie substantially along the line of the resultant tensile stress.

After the fibres have been arranged as shown in FIG- URES 1 to 4 they are hot pressed together to form, in the case of aluminium coated silica fibres, an aluminium mass reinforced by silicon fibres and to form the blades 14 integrally with the hub portion 11-13.

FIGURE illustrates a modification of the invention in which the roots of the blades 14 of the discs 12, 13, instead of being interconnected :by the lazy-tong pattern of fibres as shown in FIGURE 4, are interconnected by fibres 21 which extend from the root of a blade 14 of one of the discs to an obliquely disposed blade 14 of the other disc. The fibres 21 extend to an angle of substantially 13, to the planes of the discs 12, 13, the angle 6 being such as to make the fibers 21 lie substantially along the line of resultant tensile stress when the two discs are made to twist relatively to each other.

If desired, the blades 14 and hub portion 11-13, or parts thereof, instead of being united together simultaneously with their formation, as described above, may initially be formed separately and subsequently united.

We claim:

1. A bladed rotor comprising a hub portion, a plurality of blades united with said hub portion, at least part of each blade comprising embedded fibers, and at least part of the hub portion comprising respective continuously uniformly curved and interwoven groups of fibers connecting each respective blade to another blade, whereby the fibers of each said group are in tension along their axes on rotation of the rotor, respective pairs of said groups of fibers interconnecting respective pairs of blades and being oppositely curved, the central part of each group of a said pair of groups being spaced from the other group of said pair, and at least some of the said fibers comprising respective blades being integral with the fibers of respective groups interconnecting said pair of blades.

2. A bladed rotor as claimed in claim 1 in which all the said fibers comprising respective blades of each diametrically opposite pair of blades on the rotor are integral with the fibers of respective groups interconnecting said pair of blades.

3. A bladed rotor as claimed in claim 1 in which each continuously curved interwoven group of fibers is of catenary shape.

4. A bladed rotor as claimed in claim 1 in which the hub portion comprises at least two discs each of which carriesa plurality of blades, and a plurality of fibers interconnect the blades of each disc with those of the adjacent disc.

5. A bladed rotor as claimed in claim 1 in which the said fibers have respective individual coatings.

6. A bladed rotor as claimed in claim 1 in which the fibers are of inorganic material.

7. A bladed rotor as claimed in claim 6 in which the fibers are formed of a ceramic material.

8. A bladed rotor as claimed in claim 6 in which the fibers are formed of a material selected from the group consisting of silica, silicon nitride and silicon carbide.

9. A bladed rotor as claimed in claim 6 in which the fibers are formed of sapphire.

10. A bladed rotor as claimed in claim 6 in which the fibers are formed of boron.

11. A bladed rotor as claimed in claim 1 in which the fibers are of carbonaceous material.

12. A bladed rotor as claimed in claim 11 in which the fibers are formed from graphite.

13. A bladed rotor as claimed in claim 5 in which each fiber has an individual coating of a material selected from the group consisting of metals and alloys.

14. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of silver and any alloy thereof.

15. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of nickel and any alloy thereof.

16. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of iron and any alloy thereof.

17. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of titanium and any alloy thereof..

18. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of platinum and any alloy thereof.

19. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of columbium and any alloy thereof.

20. A bladed rotor as claimed in claim 13 in which each fiber has an individual coating of material selected from the group consisting of aluminium and any alloy thereof.

21. A bladed rotor as claimed in claim 1 in which each fiber has an individual coating of a synthetic resin material.

22. A bladed rotor as claimed in claim 21 in which the synthetic resin material is an epoxy resin.

23. A bladed rotor as claimed in claim 21 in which the synthetic resin material is a polyimide resin.

24. A bladed rotor as claimed in claim 21 in which the synthetic resin material is a polyimidazole resin.

25. A bladed rotor as claimed in claim 21 in which the synthetic resin material is a polyquinoxaline resin.

26. A bladed rotor as claimed in claim 21 in which the synthetic resin material is a polythiazole resin.

27. A bladed rotor as claimed in claim 5 in which the bladed rotor is formed of synthetic resin material reinforced by the said individually coated fibers.

References Cited UNITED STATES PATENTS 1,605,356 11/1926 Leipert. 2,405,283 8/1946 Birmann. 2,844,354 7/1958 Warnken 253-77 2,857,094 10/1958 Erwin. 2,859,936 11/1958 Warnken ,253-77 3,038,248 6/1962 Kremer 294l9 3,187,422 6/ 1965 Morgan 29-419 CHARLIE T. MOON, Primary Examiner US. Cl. X.R. 

